PRINCIPLES Op AUTOLYSIS SI 



yellow pho.splioius," iodides/' arsenic,'" CaClo/'"' salts of Kc, Mr, and cobalt/' 

 as well as salts of selenium, tclhiriuin," and manganese, ■*' colloidal sulfur'" but not 

 colloidal carbon." The favorable concentrations of these metals are very low; thus 

 the optimum proportion of arsenic is 0.007 milli^;rams i)er 1 Km. tissue, while 0.04 

 mg. inhibits autolj'sis. CO2 increases and oxyncn decreases autolysis" in vitro 

 (Laqueur). There is disagreement as to whether radium rays augment autolysis.*' 

 Injection of iodids into animals is said to increase the postmortem autolysis of 

 their tissues (Stookey, Kepinow), as also do iron salts,'"' while large doses of 

 salicylates decrease it (Laqueur). Morse" attributes the accelerating action 

 of iodin and bromin to increased acidity from formation of halogen acids, and 

 Bradley*^ finds evidence that most inorganic salts that stimulate autolysis act 

 by increasing Fl-ion concentration. Addition of tuberculin to tissues at first 

 delays and tiien increases the autolysis (Pesci^"*), and diphtheria toxin in small 

 amounts increases autolysis (Barlocco," Bertolini**), neutralization by anti- 

 toxin not preventing this effect. Lipoids also accelerate autolysis (Satta and 

 Fasiani"). According to Soula*" narcotic poisons decrease, and convulsive 

 poisons increase the rate of autolysis of nervous tissue. Glucose in one per cent, 

 concentration decreases autolysis, and this may be related to the ''protein-sparing 

 action of carbohydrates."*' E.xtracts of various ductless glands, or removal of 

 these glands from animals, seem to have but slight effect on autolysis.*- 



In considering the foregoing statements allowance must be made for the fact 

 that in most of the work cited there has been no proper consideration of H-ion 

 concentration in the autolyzing mixtures. 



Relation of Autolysis to Metabolism 



It having been shown that proteases are present in all cells, the 

 next question to be considered is, do they act only to destroy tissues 

 after death, or are they of importance in metabolism? Since it is 

 presumably necessary for proteins to be split into diffusible and easily 

 oxidized forms in order that they may enter the cell, and be built up 

 into the cell proteins, or be decomposed with the liberation of energy, 

 the autolytic proteases ma}^ be assumed to be of prime importance in 

 protein metabolism; but to prove it is another matter. Jacoby found 



" Saxl, Hofmeister's Beitr.. 1907 (10). 447; Virchow's Arch., 1910 (202), 149. 



^ Kepinow^ Biochem. Zeit., 1911 (37), 238. Kaschiwabara, Zeit. phvsiol. Chem., 

 1912 (82), 425. Not confirmed by Albrecht, Jour. Biol. Chem., 1919 (41), 111. 



^5 Izar, Biochem. Zeit., 1909 (21), 46; Laqueur and Ettinger, Zeit. physiol. 

 Chem., 1912 (79) 1. 



«Briill, Biochem. Zeit., 1910 (29), 408. 



^"Preti, Zeit. phvsiol. Chem., 1909 (GO),' 317; PoUini, Biochem. Zeit., 1912 

 (47), 396. 



" Fasiani, Arch. sci. med., 1912 (36), 436. 



^9 Bradley, Jour. Biol. Chem., 1915 (21), 209; 1915 (22), 113. 



5" Faginoli, Biochem. Zeit., 1913 (56), 291. 



*' Izar and Patane, ibid., p. 307. 



^' M. Morse found oxvgen without effect on autolysis. Biochem. Bullet., 1915 

 (5), 143. 



" See Loewenthal and Edelstein, Biochem. Zeit., 1908 (14), 485; Brown, Arch. 

 Int. Med., 1912 (10), 405. 



•■*< Kottmann, Zeit. exp. Path., 1912 (11), 355. 



"Jour. Biol. Chem., 1915 (22), 125. 



5«Cent. f. Bakt., 1911 (59), 71 and 186. 



"Cent. f. Bakt., 1911 (60), 43. 



s' Biochem. Zeit., 1913 (48), 448. 



59Berl. klin. Woch 1910 (47), 1.500. 



^oCompt. Rend. Soc. Biol., 1913 (73), 297. 



" Shaffer, Proc. Soc. Biol. Chem., 1915 (8), .xlii. 



*\Izar and Fagiuoli, Sperimentale, 1916 (70), 265. 

 6 



